I think the nest was there all along. They were hiding under the pile of rubbish and had no reasons to move out of the room since she was providing them with ample food and a conducive environment to live in. She must have ruffled their feathers when she tried to clear up the rubbish. Thats when shit hits the fan, and they all scattered all over the place once she started disrupting their nest.

Next time in school Kemahiran Hidup should include classes to teach ppl how to clean up the house and proper sanitary education.

who would be so free to harass her on her phone number??
At most would be the house agent or her housemates, affected by her actions.